How to Vibrate while typing but not when pressing the backspace key

Question

I have the following code:

@SuppressWarnings("unchecked")
        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            data = (ArrayList<SetRows>)results.values;
            EditText etS = (EditText) ((Activity)context).findViewById(R.id.etSearch);
            if (data.isEmpty()) {
                etS.setTextColor(Color.parseColor("#FFCC0000"));
                Vibrator vb = (Vibrator) ((Activity)context).getSystemService(Context.VIBRATOR_SERVICE);
                // Vibrate for 100 milliseconds
                vb.vibrate(100);
            }
            if (!data.isEmpty()) {
                etS.setTextColor(Color.parseColor("#FF27497B"));
            }
            notifyDataSetChanged();
            clear();
            for(int i = 0, l = data.size(); i < l; i++)
                add(data.get(i));
            notifyDataSetInvalidated();
        }

It vibrates every time I enter a character which doesn't match anything in the ListView and it's working fine. The issue is, it also vibrates when I press the backspace/delete key. Which is not the intention.

How do I allow the vibrate while entering the wrong letter, but not when pressing backspace/del key. I tried the onTextChanged but that wasn't working.

Answer 1

I'd keep the length of entered text. When pressing backspace/delete, you're basically erasing last character (the length is decreasing), so compare the new length with an old one. Pseudocode:

if newLength > oldLength then vibrate

else don't vibrate 

If newLength is shorter, it means you have pressed backspace/delete key and deleted a character, so don't vibrate. You can do it in onTextChanged, or where ever makes sense to you.